Trancriptome Analysis of Testis and Liver for Androstenone by Using RNA Sequencing

Boar taint is an unpleasant odor and flavour of the meat. Boar taint occurs in a high proportion of uncastrated male pigs due to high level of accumulation of androstenone and skatole in the adipose tissue. It is important to understand the genetic mechanism controlling boar taint in order to select pigs for lower androstenone level and thus limit the occurrence of boar taint. The aim of the present study was to perform a comparative trancriptome analysis in testis and liver of boars with divergent androstenone level using the RNA-Seq technology. For this purpose total RNA was isolated from testis and liver of 10 Duroc × F2 boars. Five pigs with extreme high and 5 pigs with extreme low level androstenone were selected from 100 entire male pigs. First and second strand cDNA was synthesized and sequenced using Illumina HiSeq 2000 platform. A total of 1.620.570 expression sequence tags (ESTs) were generated from cDNA libraries design to represent the known pig trancriptome.  The total number of reads produced for each testis and liver sample ranged from 13.221.550 to 15.605.400 and 12.177.716 to 16.420.055, respectively. Results showed that 223 and 67 genes that were differentially expressed (p<0.01) in testis and liver, respectively. Testis and liver associated with lower androstenone revealed group of genes, involved in the nuclear receptor, metabolism of xenobiotics by cytochrome P450 and fatty acid metabolism. Moreover, a number of genes encoding biosynthesis of steroids were highly expressed in testis with lower androstenone. This study provides evidence for transcriptome profile and genetic networks of boars with divergent androstenone level using RNA-Seq technology. Further studies are warranted for proofing the role of candidate genes to be used in genomic selection programs for reducing the boar taint in pig breeding programs.